Method of treating pistons



[ dllllllUl y July 25, 1944. H, p PHlLLlPs 2,354,275

METHOD OF TREATING PISTONS Original Filed April 23, 1942 2 Sheets-Sheet 1 INVENTOR.

Lw www July 25, 1944. H. P. PHILLIPS 2,354,275

METHOD OF TREATING PISTONS Original Filed April 23, 1942 2 Sheets-Sheet 2 Patented July 25, 1944 txarnl'ner METHOD F TREATING PISTONS Harold P. Phillips, Hastings, Mich., assigner to Hastings Manufacturing Company, Hastings, Mich., a corporation of Michigan Original application April 23, 1942, Serial No. 440,236. Divided and this application January 2, 1943, Serial No. 471,119

(Cl. 2li-156.5)

8 Claims.

This invention relates to improvements in method of treating pistons.

This application is a division of my application for Letters Patent filed April 23, 1942, Serial No. 440,236.

The main objects of this invention are:

First, to provide a method for treating pistons which results in effectively offsetting a, longitudinal area of a piston skirt without inducing or producing in the piston distortion stresses which might result in ultimate fracturing of the piston wall or in changing its shape.

Second, to provide a method for treating pistons which may be successfully practiced by persons other than highly skilled mechanics or workmen.

Third, to provide a method for treating pistons for internal combustion engines which enables worn pistons or standard-size pistons being adapted for use in a rebored cylinder or in a worn cylinder.

Fourth, to provide a method by which the amount of offset in the piston skirt can be accurately gauged.

Filth, to provide a method of treating pistons which may be successfully practiced on a large scale.

Certain steps of my method and an apparatus for practicing the same are illustrated in the accompanying drawings, in which:

Fig. l is a fragmentary view of a machine or apparatus without work therein or with the parts in unloaded position.

Fig. 2 is an enlarged fragmentary view in section on a line corresponding to the broken line 2-2 of Fig. 5 with a piston in operative position at the completion of the steps of the method.

Fig. 3 is a side elevation of a piston which has been treated by my method.

Fig. 4 is an enlarged fragmentary view showing certain details of the apparatus used in per forming or practicing my method.

Fig. 5 is an enlarged fragmentary view partially in section on line 5-5 of Fig. 2.

I will describe the apparatus illustrated for performing the steps of my method along with the steps of the method.

I'he table or bench I is mounted on suitable legs or standards 2. At one end of the table is a pair of laterally spaced work supports 3 having angular work engaging portions 4 with slots or notches 5 therein, there being a plurality or series of these notches as is clearly shown in Figs. 2 and 5. These work supports are adapted to receive a piston 6 and support the skirt I thereof at laterally spaced zones longitudinally of the pist0n. These work supports extend substantially the full length of the piston as is shown in Fig. 5 and support it at these areas.

The table I is provided with a laterally disposed portion l having an `upright web 9 thereon. Plates Ill are bolted to this web 8 to provide an upwardly facing groove-like holder. The upper face or bottom II of this holder is upwardly inclined-see Fig. 5.

An outer or anvil die member I2 is provided, this die member having a downwardly facing longitudinal groove I3 therein which receives the upper edge of the adjusting member I4, the bottom I5 of which is inclined complementary to the inclined face of the holder so that by adjusting the member i4 longitudinally of the holder the outer or anvil die member is raised or lowered. This anvil die member has a face I6 convexly curved in cross section, this face being substantially narrower than the width of the space between the piston supports 4.

The anvil die member has a series of notches Il which open to the face thereof, see Figs. 2 and 5.

'I'he adjusting member I4 is adjusted by means of the screw IB having a linger piece I9 at its outer end, the screw being threaded through the bracket 20 and having a swivel connection to the member I4 so that the member I4 may be adjusted in both directions. This connection is not illustrated. This screw has an indicia. member 2| having a micrometer screw indicating thirtythousandths of an inch. An index finger or pointer 22 is mounted on the screw and adjustably associated with the scale or gauging indicia.

After the piston has been positioned on the support members 3, the screw I8 is adjusted until the anvil die member is brought into contact with the skirt of the piston. The index finger is then adjusted, preferably to a top position where it can be easily viewed and the screw backed off to the desired degree. For example, if it is desired to oiset the piston thirty-thousandths of an inch the thumb piece would be given one complete rotation. The next step is to position the inner die or thrust member 23 within the piston in its opposed relation to the anvil die member and the thrust or actuating member 24 is adjusted to bring its arm 25into overhanging relation to the die member 23, see Figs. 2 and 5. The arm 25 is provided with a spherical contact member 26 which coacts with a socket 21 in the die member 23 so that there is in eilect a. ball and socket engagement between these members.

The member 24 is supported in a slot 28 in the bracket or frame piece 28 both for horizontal movement to bring the arm 25 into and out of operative position and also to permit vertical movement for applying the actuating thrust to the die member. For this purpose I associate the actuating lever 30 with the arm 3| on the lower end of the thrust member.

The lever 30 is pivoted at 32 on a pair of spaced bracket ears 33, the pivot 32 being selectively engageable with a series of vertically spaced holes 34 in these ears 32.

It will be noted that the lever engages the arm 3| very close to the pivot so that a very powerful lever action results. This permits the use of a relatively light actuating weight 35 for the lever. The weight is preferably used so as to secure a uniform thrust or actuation of the thrust die member. The weight is provided with eyes 36 which are slidable on the lever toward and from its pivot or fulcrum 32. Lateral swaying movement of the lever is prevented by the pair of upwardly projecting arms or uprights 31 and 38 disposed near the outer end of the table.

A threaded stop 39 provided with a knurled finger piece 40 is disposed near the inner end of the lever to limit the downward stroke or movement thereof or to stop its downward stroke or movement during the forming operation.

In adjusting, the weight 35 is preferably moved inwardly on the lever. The thrust member is in retracted position, as shown in Fig. 2, then the work is placed upon the supports. The inner die member or thrust die member is then positioned within the work and the thrust member 24 moved horizontally to position its arm 25 above the die member and so that when actuated the spherical thrust member 26 will engage the socket 21.

Burners 4| connected to a suitable gas supply, preferably provided with a control valve 42, is provided. These burners are positioned so that the flames thereof are directed upwardly between the downwardly diverging sides 43 of the support members 3 and at either side of the anvil die member I 2. The series of notches in the support members and the anvil die members facilitate the heating the portion of the piston skirt adjacent the supported zones thereof.

With the work in position and the outer or anvil die member properly in position relative to the work, as has been described, the burners are lighted and the weight 35 moved outwardly to operative position-that is, to a position which with the associated parts give a desired amount of thrust pressure to the thrust die member. As soon as the metal becomes sufficiently heated, the actuating lever, actuated through its Weight, will offset the portion of the piston between the supports, as indicated at 44, until the offset portion contacts the outer anvil or die member.

'Ihe actuating pressure for the thrust die member is insufficient to effect such offsetting until the metal of the piston is substantially softened by the heating thereof adjacent the supported zones.

It will be noted that the die members are of less width than the distance between the pistons. This results in the offsetting taking place in the desired restricted area. 'Ihe piston skirt is supported between the die members so that it is not distorted or heated to such degree as will cause distortion or warping.

In order that the operator may better observe the offsetting action or the heating action, I provide a graduated scale 45 with a pointer 46 which is pivot/ed at 41. This pointer has a counterweight 48 which is merely intended to counterbalance the pointer on its pivot. 'I'his pointer is connected by the link 49 to the lever 30 which is adjustably connected to the outer end of the actuating lever by means of a thumb screw, not illustrated.

With this arrangement. as soon as the lever 30 begins to travel downwardly as results from the softening of the metal to the desired point, the

pointer begins to swing upwardly and if this movement is too rapid-that is, if it indicates overheating of the work, the operator can adjust the valve 42. Another safety factor is the adjustable stop 39 which, in the event the operator is of the opinion that the work has been sufficiently heated or is becoming excessively heated, he can adjust the screw to stop the action of the lever. These features are aids to avoid injury to the work and as a matter of convenience for the workmen.

I have described the various steps of my method in connection with the apparatus illustrated but it will be understood that they can be practiced with other apparatus. This apparatus, however, which is the subject matter of my application for patent referred to is highly desirable for practicing my method. By the practice of my method, pistons can be treated Without subjecting the metal thereof to undesirable stresses such as frequently result from variously practiced hammering and distortion methods, and by following out the method pistons may be resized or treated in a very uniform manner to produce offsetting measured by the thousandths of an inch.

A further advantage is that the method may be practiced by relatively unskilled Workmen without the danger of injuring the work.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The method of treating pistons comprising supporting the piston at laterally spaced longitudinal areas thereof with the portion of the piston skirt between the areas in opposed relation to an anvil die member having a face concavely curved in cross section and disposed centrally relative to the laterally spaced support areas of the piston skirt and spaced therefrom a predetermined amount, positioning a thrust die member having a face convexly curved in cross section within the piston in opposed relation to said anvil die member and with the longitudinal edges thereof in spaced relation to the laterally spaced supported areas of the piston skirt, ap-

, plying a predetermined pressure to said thrust die member, and heating the piston skirt adjacent the supported areas thereof and adjacent the edges of said thrust die member to such degree that said predetermined pressure of the thrust die member will offset the portion of the piston skirt between the supported areas thereof and into engagement with the anvil die member, the amount of pressure applied to the thrust die member being insufficient to effect such offsetting until the metal of the piston is substantially softened by the heating thereof in said restricted zones, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

2. The method of treating pistons comprising supporting the piston at laterally spaced longitudinal areas thereof with the portion of the piston skirt between the areas in opposed relation to an anvil die member and spaced therefrom a predetermined amount, positioning a thrust die member having a face within the piston in opposed relation to said anvil die member and with the longitudinal edges thereof in spaced relation to the laterally spaced supported areas of the piston skirt, applying a predetermined pressure to said thrust die member, and heating the piston skirt adjacent the supportedareas thereof and adjacent the edges of said thrust die member to such degree that said predetermined pressure of the thrust die member will offset the portion of the piston skirt between the supported areas thereof and into engagement with the anvil die member, the amount of pressure applied to the thrust die member being insufficient to effect such offsetting until the metal of the piston is substantially softened by the heating thereof in said restricted zones, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

3. The method of treating pistons comprising supporting the piston' at laterally spaced longitudinal areas thereof with the portion of the piston skirt between the areas in opposed relation to an anvil die member having a face concavely curved in cross .section and disposed centrally relative to the laterally spaced support areas of the piston skirt and spaced therefrom a predetermined amount, positioning a thrust die member having a face convexly curved in cross section within the piston in opposed relation to said anvil die member and with the longitudinal edges thereof in spaced relation to the laterally spaced supported areas of the piston skirt, applying a predetermined pressure to said thrust die member, and heating the piston skirt adjacent the supported areas thereof and adjacent the edges of said thrust die member to such degree that said predetermined pressure of the thrust die member will offset the portion of the piston skirt between the supported areas thereof and into engagement with the anvil die member, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

4. The method of treating pistons comprising supporting the piston at laterally spaced longitudinal areas in opposed relation to an anvil die member and spaced therefrom a predetermined amount, positioning a thrust die member within the piston in opposed relation to said anvil die member and with the longitudinal edges thereof in spaced relation to the laterally spaced supported areas of the piston skirt, applying a predetermined pressure to said thrust die member, and heating the piston skirt adjacent the supported areas thereof and adjacent the edges of said thrust die member to such degree that the thrust die member will offset the portion of the piston skirt between the supported areas thereof and into engagement with the anvil die member, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

5. The method of treating pistons comprising supporting the piston at laterally spaced longitudinal areas thereof with the portion of the piston between the areas in opposed relation to an anvil die member disposed centrally relative to the laterally spaced support areas of the piston skirt and spaced therefrom a predetermined amount, positioning a thrust die member within the piston in opposed relation to said anvil die member and with the longitudinal edges thereof in spaced relation to the laterally spaced supported areas of the piston skirt, applying pressure to said thrust die member, and heating the piston skirt in relatively restricted areas thereof between the anvil die member and the supported areas thereof and adjacent the edges of said thrust die member to such degree that the thrust die member will offset the portion of the piston skirt between the supported areas thereof and into engagement with the anvil die member, the amount of pressure applied to the thrust die member being insufficient to effect such offsetting until the metal of the piston is substantially softened by the heating thereof in said restricted zones, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

6. The method of treating pistons comprising supporting the piston at laterally spaced longitudinal areas thereof with the portion of the piston between the arms in opposed relation to an anvil die member disposed centrally relative to the laterally spaced support areas of the pis ton skirt and spaced therefrom a predetermined amount, positioning a thrust die member within the piston in opposed relation to said anvil die member and with the longitudinal edges thereof in spaced relation to the laterally spaced supported areas of the piston skirt, applying pressure to said thrust die member, and heating the piston skirt in relatively restricted areas thereof between the anvil die members and the supported areas thereof and adjacent the edges of said thrust die member to such degree that the thrust die member will offset the portion of the piston skirt between the supported areas thereof and into engagement with the anvil die member, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

'7. The method of treating pistons comprising supporting the piston at laterally spaced areas of the piston skirt longitudinally thereof and with the portion of the piston skirt between such support areas in opposed relation to an anvil die member which is spaced from the piston a predetermined amount, positioning a thrust die member within the piston in opposition to the anvil die member, applying pressure to said thrust die member, and heating the work adjacent the supported zones thereof to such degree that the thrust die member will offset the portion of the piston between the supported zone thereof into engagement with the anvil die member, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

8. The method of treating pistons comprising supporting the piston at laterally spaced areas of the piston skirt longitudinally thereof and with the portion of the piston skirt between such support areas in opposed relation to an anvil die member which is spaced from the piston a predetermined amount, positioning a thrust die member within the piston in opposition to the anvil die member, and applying pressure to said die member and heating the work adjacent the supported zones thereof to such degree that the portion of the piston between the supported zone is offset into engagement with the anvil die member, said heating of the skirt being while said pressure is applied to the same, and said heating being of greatest intensity in the portions of the skirt to be offset.

HAROLD P. PHILLIPS. 

